Open CFR implemented in the LEDUC card game

This is the current home of Kevin Waugh's Open CFR implemented for the
Leduc card game. The source code is written in C++ and is licensed under the
Open BSD License. The README in the tarball contains information on training
and playing strategies created using this code as well as some examples. There
are also a handful of abstractions in the abstractions folder. The link for the
tarball is below: